feature: V2 Permissions (#2222)

* Initial V2 permissions

* add perms-v2 attributes and properties, add deprecation messages

* add perms-v2 properties to command info classes

* add perms-v2 fields to Rest/SocketApplicationCommand entities and IApplicationCommand

* fix json name of DmPermission field

Co-authored-by: Cenngo <cenk.ergen1@gmail.com>

src/Discord.Net.WebSocket/Entities/Interaction/SocketBaseCommand/SocketApplicationCommand.cs

@@ -36,6 +36,12 @@ namespace Discord.WebSocket
         /// <inheritdoc/>
         public bool IsDefaultPermission { get; private set; }
 
+        /// <inheritdoc/>
+        public bool IsEnabledInDm { get; private set; }
+
+        /// <inheritdoc/>
+        public GuildPermissions DefaultMemberPermissions { get; private set; }
+
         /// <summary>
         ///     Gets a collection of <see cref="SocketApplicationCommandOption"/>s for this command.
         /// </summary>
@@ -86,6 +92,10 @@ namespace Discord.WebSocket
             Options = model.Options.IsSpecified
                 ? model.Options.Value.Select(SocketApplicationCommandOption.Create).ToImmutableArray()
                 : ImmutableArray.Create<SocketApplicationCommandOption>();
+
+            IsEnabledInDm = model.DmPermission.GetValueOrDefault(true).GetValueOrDefault(true);
+            DefaultMemberPermissions = model.DefaultMemberPermission.IsSpecified
+                ? new GuildPermissions((ulong)model.DefaultMemberPermission.Value) : GuildPermissions.None;
         }
 
         /// <inheritdoc/>